Silver halide photographic materials containing 1-arylmethyl-2-pyrazolin-5-one color couplers

ABSTRACT

COLORLESS MAGENTA FORMING COLOR COUPLERS OF THE 2PYRAZOLIN-5-ONE TYPE HAVING FORMULA:   1-(AR-CH2-),3-(R-CO-HN-)-2-PYRAZOLIN-5-ONE   WHEREIN: AR REPRESENTS AN ARYL GROUP, AND R REPRESENTS AN ALKYL RADICAL, AN ARYL RADICAL, AN ARALKYL RADICAL, AN ALKOXY RADICAL, IN ARYLOXY RADICAL, AN ARALKYLOXY RADICAL, AN ALKYLAMINO RADICAL AN ARYLAMINO RADICAL OR AN ANALKYLAMINO RADICAL ARE DESCRIBED. THESE COLOR COUPLERS HAVE IMPROVED STABILITY WHEN STORED IN HUMID AND WARM ATMOSPHERES AND THE WHITE IMAGE AREAS DO NOT UNDERGO DISCOLORATION.

United States Patent Office US. Cl. 96-565 5 Claims ABSTRACT OF THE DISCLOSURE Colorless magenta forming color couplers of the 2'- pyrazolin-S-one type having the formula:

Ar a

ll H2O CNHGOR wherein Ar represents an aryl group, and

R represents an alkyl radical, an aryl radical, an aralkyl radical, an alkoxy radical, an aryloXy radical, an aralkyloxy radical, an alkylamino radical, an arylamino radical or an analkylamino radical are described. These color couplers have improved stability when stored in humid and warm atmospheres and the white image areas do not undergo discoloration.

This invention relates to colour photography and the production of photographic colour images by colour development. It relates more particularly to novel colourless magenta-forming colour couplers of the 2-pyrazolin-5-one type and to photographic materials and developing compositions containing such colour couplers.

It is known that for the manufacture of a photographic colour image in a light-sensitive silver halide emulsion layer the exposed silver halide is developed to a silver image by means of an aromatic primary amino compound in the presence of a colour coupler which by reaction with the oxidized developer forms a dye on the areas corresponding with the silver image.

In the subtractive three-colour photography usually a light-sensitive photographic colour material is used comprising a red-sensitized, a green-sensitized and a blue-sensitive silver halide emulsion layer wherein on development by means of suitable colour couplers, a cyan, a magenta, and a yellow dye image are formed respectively.

The present invention is concerned with a process for the production of photographic colour images using magenta-formin g colour couplers of the 2-pyrazolin-5-0ne type, which show an improved stability when stored in humid and warm atmospheres and do not give rise to colouring of the white image areas and which on colour development with aromatic primary amines as developing agents form azomethine magenta dyestuffs possessing favourable spectral properties and having an improved light-stability, a good colour density and good gradation.

The present invention also relates to photographic materials and treating solutions comprising said colour couplers, by means of which magenta dye images are formed.

The colour couplers for magenta of the 2-pyrazolin-5- 3,563,745 Patented Feb. 16, 1 971 one type of use according to the present invention correspond to the following general formula:

Ar represents an aryl group, including aryl substituted by one or more non-chromophoric groups, e.g. a halogen atom such as chlorine, a cyano group, an alkoxy group such as methyloxy, an aryloxy group, a trifiuoromethyl group, an alkyl mercapto group such as methyl mercapto, an aryl mercapto group, an alkylsulphonyl group such as methylsulphonyl and an arylsulphonyl group, and

R represents an alkyl radical, an aryl radical, an aralkyl radical, an alkoxy radical, an aryloxy radical, an aralkyloxy radical, an alkylamino radical, an arylamino radical or an aralkylamino radical including the substituted derivatives of these radicals.

The following is a non-limitative list of structural formulae of colour couplers corresponding to the above general formula and suitable for use according to the present invention:

0- CH CH 2)n a I w N SOaH I r N No. 1,044,959 filed Sept. 28, 1964 and No. 1,007,847 filed Oct. 10, 1963 both by Gevaert Photo-Producten NV. and in German patent application (DAS) 1,176,479 filed Dec. 20, 1963 by Perutz Photowerke G.m.b.H.

The 1-arylmethyl-3-amino-2-pyrazolin-5-one compounds used are prepared according to the method known by those skilled in the art i.e. by cyclisation of an appropriate arylmethyl-hydrazine with, -e.g., the ethyl ester of B-iminofl-ethoxypropionic acid. The preparation of the arylmethyl hydrazine offers no difiiculties to the organic chemist. A

preferred method giving good yields consists in allowing to react hydrazinehydrate with a chloromethyl-substituted aromatic compound of the benzene or naphthalene series.

The following description illustrates the preparation of the magenta-forming colour couplers corresponding to the above general formula.

PREPARATION 1 1-benzyl-3 -octadecylureido-2-pyraz0lin-5-one (Formula 2) (a) 1=benzyl-3-amino-2-pyrazolin-5-one.--To a solution of 122 g. of benzylhydrazine, prepared as described by J. H. Biel et al., J. Am. 'Chem. Soc. 81, 2805 (1959), in 570 ml. of water, 159.5 g. of fi-ethoxy-fi-iminopropionic acid ethyl ester and 1 g. of p-toluene-sulphonic acid are added while stirring. The temperature of the reaction mixture rises slowly and is kept at 30 C. by cooling periodically. A clear solution forms but after 1 hour a white product precipitates. The reaction mixture is then kept standing overnight whereupon the solid is separated and thoroughly washed with water. The white fibrous crystalline product melts at 139140 C.

(b) 1-benzyl-3 -octadecylureido-2-pyrazolin-5-one.-1 8 .9 g. of 1-benzyl-3-amino-2-pyrazolin-5-one and 29.5 g. of octadecyl isocyanate are allowed to react at 36 C. in 100 ml. of methylene chloride and in the presence of 26.7 g. of aluminium chloride (this method has been described in United Kingdom patent specification No. 1,007,847 filed Oct. 10, 1963 by Gevaert Photo-Producten N.V.).

The reaction product is washed with water and with methanol and then recrystallized from isopropanol. The colour coupler formed is a white product having a melting point of 131 C.

PREPARATION 2 1- 2-chlorob enzyl) -3 o-hexadecylsulphonylbenzamido 2-pyrazolin-5-one (Formula 5) (a) 1-(2 chlorobenzyl)-3-amino-2-pyrazolin-5-one. 156.5 g. of 2-chlorobenzylhydrazine, which is a colourless liquid with a boiling point of 85 C./ 0.25 mm. and which has been prepared analogously to the method described by J. H. Biel et al., J. Am. Chem. Soc. 81, 2805 (1959), are mixed with 159.5 g. of ,fi-ethoxy-p-imino-propionic acid ethyl ester and 2 ml. of acetic acid. The temperature of the reaction mixture rises to 45 C. The mixture is kept standing overnight whereupon the precipitate formed is filtered by suction and washed with acetonitrile. A white product with a melting point of 163 C. is obtained.

(b) 1 (2 chlorobenzyl) 3-(o-hexadecylsulphonylbenzamido)-2-pyrazolin-5-one.- 22.35 g. of 1-(2-chl0robenzyl)-3-amino-2-pyrazolin-5-one and 42.85 g. of o-hexadecylsulphonylbenzoylchloride are allowed to react at 36 C. in 100 ml. of methylene chloride and in the presence of 26.7 g. of aluminum chloride (this method has been described in United Kingdom patent specification No. 1,007,847 filed Oct. 10, 1963 by Gevaert Photo-Producten N.V.).

The reaction product is washed with water and then treated with acetonitrile. A white product is obtained, which after having been washed with isopropyl ether melts at 100 C.

PREPARATION 3 1-(4-chlorobenzyl)-3-palrnitoylarnino-2-pyrazolin-5-one (Formula 7) (a) 1-(4-chlorobenzyl)-3-amino-2-pyrazolin-5-one is prepared in an analogous way as 1-(2-chlorobenzyl)-3 amino2-pyrazolin-5-0ne (preparation 2(a)) starting, however, from 4-chlorobenzylhydrazine which is a colourless liquid having a boiling point of 99-102 C./0.7 mm. The 1 (4-chlorobcnzyl)-3-amino-2-pyrazolin-S-one obtained after recrystallisation from ethanol is a white product that melts at 138 C.

(b) 1-(4-chlorobenzyl) 3 palmitoylamino-Z-pyrazolin-5-one.-22.35 g. of 1-(4-chlorobenzyl)-3-amino-2-pyrazolin-S-one and 27.48 g. of palmitoyl chloride are allowed to react at 50 C. in ml. of nitrobenzene and in the presence of 26.7 g. of aluminium chloride (this method has been described in United Kingdom patent specification No. 1,007,847 filed Oct. 10, 1963 by Gevaert Photo-Producten N.V.).

The reaction product is washed with water and with methanol and then recrystallized from a mixture of isopropanol and ethylene glycol monomethyl ether. A white product is obtained having a melting point of C.

PREPARATION 4 1- 3-trifluoromethylbenzyl -3- ot-sulpho-stearoylamino 2-pyrazolin-5-one (Formula 8 (a) 1-(3-trifluoromethylbenzyl) 3 amino-Z-pyrazolin-5-one.3-trifiuoromethylbenzyl bromide prepared as described in J. Org. Chem. 25, 733 (1960) is converted into 3-trifiuoromethyl-benzylhydrazine analogously to the method described by J. H. Biel et al., J. Am. Chem. Soc. 81, 2805 (1959). This benzylhydrazine is a colourless liquid with a boiling point of 93 C./ 0.35 mm. From this benzylhydrazine and B-ethoxy-[3-imino-propionic acid ethyl ester, 1-( 3-trifluoromethyl benzyl -3-amino-2-pyrazolin-5- one is prepared in an analogous way as described for 1-(2- chlorobenzyl)-3-amino-2-pyrazolin-5-one in preparation 2(a). The product obtained after recrystallisation from a mixture of isopropyl ether and methyl acetate melts at 146 C.

(b) l (3 trifluoromethylbenzyl) 3 (a sulphostearoylamino)-2-pyrazolin-5-one.25.7 g. of 1-(3-trifluoromethylbenzyl)-3-amino-2-pyrazolin-5-one and 39 g. of the monosodium salt of Z-sulpho-stearic acid are allowed to react analogously to the method described in US. patent specification No. 2,829,975 of Stanley P. Popeck and Heinz Schulze, issued Apr. 8, 1958 in 80 ml. of pyridine and 160 ml. of benzene and in the presence of 4.5 ml. of phosphorus trichloride. A white product is obtained that does not melt at a temperature lower than 200 C.

PREPARATION 5 1- (2,6-dichlorobenzyl -3- 2-hexadecyloxy-5-sulphobenzamido)-2-pyrazolin-5-one (Formula 9) (a) 1-(2,6-dichlorobenzyl) 3 amino-2-pyrazolin-5- one.2,6-dichloro-benzylhydrazine, which is a colourless liquid boiling at 109 C./1 mm. and prepared analogously to the method described by I. H. Biel et al., J. Am. Chem. Soc. 81, 2805 1959), is converted into 1-(2,6-dichlorobenzyl)-3-amino-2-pyrazolin-5-one in an analogous way as 1-(2-ch1orobenzyl)-3-amino-2-pyrazolin-5-one (preparation 2(a) After recrystallisation from a mixture of isopropyl ether and acetic acid the product melts at 230232 C.

(b) 1-(2,6-dichlorobenzyl) 3 (2 hexadecyloxy-S- sulpho-benzamido)-2-pyrazolin-5-one.25.8 g. of 1-(2,6- dichlorobenzyl)-3-amino-2-pyrazolin-5-one are allowed to react, analogously to the method described in US. patent specification 2,829,975 of Stanley P. Popeck and Heinz Schulze, issued Apr. 8, 1958, with 44.2 g. of 2-hexadecyloxy-S-sulpho-benzoic acid, prepared analogously as 2-hexadecyloxy-3-sulpho-benzoic acid described in United Kingdom patent specification No. 1,039,965 filed July 6, 1964 by Gevaert Photo-Producten N.V., in 80 ml. of pyridine and 160 ml. of benzene and in the presence of 4.5 ml. of phosphorus trichloride.

A white product is obtained that does not melt at a temperature lower than 200 C.

The colour couplers for magenta according to the present invention may be of the diffusible type as well as of the non-dilfusible type. By diffusible-type couplers is meant couplers the dispersability or solubility of Which is sufficient to enable them to :be usefully incorporated in aqueous colour developing baths; an example of such a colour coupler is the colour coupler according to Formula 1. By non-diffusing colour couplers is meant colour couplers of such nature that they are capable of remaining during colour development in the photographic hydrophilic colloid layer(s) in which they have been incorporated. For manufacturing an appropriate photographic multilayer colour material containing colour couplers for each colour separation image in the differently optically sensitized silver halide emulsion layers, the colour couplers must be present in the hydrophilic silver halide emulsion layers in a non-diffusible form. This object can be accomplished e.g. by the use of a sufiiciently water-soluble colour coupler comprising an organic radical which is sufficiently large to prevent the colour coupler from diffusing in the hydrophilic silver halide emulsion layer, or by the utilization of a lipophilic colour coupler, which, in dissolved state in a high-boiling organic solvent, is dispersed in the silver halide emulsion layer. According to the present invention the said radical rendering the colour coupler non-diifusible or non-migratory may be present in the radical Ar or R of the above general formula and is preferably an aliphatic radical containing. from 5 to 20 carbon atoms in straight line.

For the purpose of incorporating the colour couplers into a photographic colloid layer the couplers may be dissolved either in a low-boiling water-insoluble organic solvent or in an appreciably water-soluble organic solvent and can be finely dispersed in a photographic colloid, e.g., gelatin. Particularly useful dispersing techniques which can be applied are described in our British Patent Nos. 1,098,594; 1,099,414; 1,099,415; 1,099,416, and 1,099,417. A particular colour coupler according to the present invention may be incorporated into a silver halide emulsion according to any other appropriate technique known in the art.

In the preparation of a light-sensitive colour material wherein non-migratory colour couplers are used these colour couplers are mixed homogeneously with the lightsensitive silver halide emulsion preferably immediately before the coating of the emulsion.

The couplers according to the above general formula may be used in various kinds of photographic emulsions. They may be added to the emulsions before or after any sensitizing dyes are incorporated. Various silver salts may be used as the sensitive salt, such as silver bromide, silver iodide, silver chloride, or mixed silver halides, such as silver chlorobromide and silver bromoiodide. The colour couplers may be incorporated into emulsions of the mixed packet type such as described in the U.S. patent specification 2,698,794 of Leopold Godowsky, issued Jan. 4, 1955 or into emulsions of the mixed grain type, such as described in the U.S. patent specification 2,592,243 of Burt H. Carroll and Wesley T. Hanson, Jr., issued Apr. 8, 1952. The colour couplers can be used in emulsions wherin latent images are formed predominantly on the surface of the silver halide crystal or in emulsions wherein latent images are formed predominantly inside the silver halide crystal.

The coupler compounds of the present invention may be dispersed in any water-permeable hydrophilic colloid material, such as gelatin, albumin, casein, zein and the like, and synthetic hydrophilic colloids, such as polyvinyl alcohol, that may be used for making photographic emulsions. The emulsions usually also comprise i.a. spectrally sensitizing agents, hardeners, stabilizing agents and wetting agents, for facilitating the coating and the adhesion of the emulsion. The thus prepared silver halide emulsion can be coated as one of the layers of a onelayer or multilayer colour material.

The non-migratory colour couplers according to the present invention need not necessarily be provided in the light-sensitive silver halide emulsion layer, but they may also be incorporated into a non-light-sensitive colloid layer adjacent to a silver halide emulsion layer or into a colloid layer in water-permeable relationship therewith.

The non-migratory colour couplers for magenta described in the present invention are added, usually as a solution to a green-sensitized silver halide emulsion. According to a common procedure in the art this silver halide emulsion is coated as the second colour coupler containing layer of a photographic multilayer colour material. Such photographic multilayer colour material usually consists in the given sequence of a support, a red-sensitized silver halide emulsion layer with a colour coupler for cyan, a green-sensitized silver halide emulsion layer with a colour coupler for magenta and a blue-sensitive silver halide emulsion layer with a colour coupler for yellow.

A yellow filter layer generally comprising colloidal silver dispersed in gelatin is provided usually between the silver halide emulsion layer containing a colour coupler for yellow and the green-sensitized silver halide emulsion layer.

The colour couplers for magenta according to the present invention may also be applied in so-called droplet emulsions (cf. U.S. patent specification 2,304,940 of Leopold D. Mannes and Leopold Godowsky, Jr., issued Dec. 15, 1942).

Photographic emulsions containing these couplers may be coated on a transparent support such as glass, cellulose esters or on a non-transparent reflecting material such as paper or an opaque cellulose ester.

For the production of photographic colour images according to the present invention an exposed silver halide emulsion layer is developed preferably with an aromatic primary amine developing substance in the presence of a colour coupler for magenta corresponding to the above general formula.

Suitable developing agents are aromatic amine compounds, such as p-phenylene diamine, N,N-dialkyl-pphenylenediamines, such as N,N-diethyl-p-phenylenedi amine, and derivatives such as N,N-dialkyl-N'-sulphomethyl-p-phenylenediamines and N,N-dialkyl-N-carboxymethyl-p-phenylenediamines.

The magenta dye images formed on colour development show good fastness to light, an intense colour density and favourable spectral properties.

The following example illustrates the use of the magenta forming colour couplers according to the present invention.

EXAMPLE T0 1 kg. of a green-sensitized silver chloride emulsion containing an amount of silver chloride equivalent to 20 g. of silver nitrate are added 50 g. of the colour coupler of Formula 6, dissolved in a mixture of 500 ml. of ethanol, m1. of 2 N sodium hydroxide and 425 ml. of distilled water. The pH of the emulsion is adjusted to pH 7.6 and then the usual additives are incorporated such as hardeners, coating aids, wetting agents and stabilizers. The emulsion is coated on a baryta-coated paper supporting such a way that 60 sq. m. are covered and then dried.

After exposure through a grey-wedge the light-sensitive colour material is developed in a developing bath of the following composition:

G. p-N,N-diethylaminophenyl ammonium chloride 2.75

Sodium sulphite (anhydrous) 4 Sodium carbonate (anhydrous) 50 Potassium bromide 0.65 Hydroxyammonium chloride 3 Sodium hexametaphosphate 2.0

Water to 1000 ccs. (pH: 10.6).

The developed colour material is rinsed for 30 seconds and fixed in an acid fixing bath of the following composition:

G. Sodium thiosulphate (anhydrous) 100 Sodium sulphite (anhydrous) Sodium hydrogen sulphite (anhydrous) Water to 1000 ccs.

Now the fixed material is rinsed for 10 minutes and bleached in a bath of the following composition:

Ethylene-diamine-tetraacetic acid sodium iron (III) salt 37.5 Ethylene-diamine-tetraacetic acid sodium salt 21.5 Ammonium thiocyanate (anhydrous) 110 Amonium thiocyanate (anhydrous) 5 Sodium sulphite (anhydrous) 10 Water to 1000 ccs.

Finally the bleached material is rinsed for 5 minutes and stabilized in a bath of the following composition:

Sodium diacetate (NaOOCCH -CH COOH)3 g. Sodium acetate-12 g.

40% by weight aqueous formaldehyde solution-240 ccs. Water to1000 ccs.

The material is dried.

A magenta wedge image is obtained.

We claim:

1. Method of producing a magenta coloured photographic image in a photographic light-sensitive silver halide material, which comprises exposing the material and developing it in the presence of a colourless coupler compound corresponding to the general formula:

wherein:

Ar represents an aryl group, and

5 R'represents an alkyl radical, an aryl radical, an aralkyl radical, an alkoxy radical, an aryloxy radical, an aralkyloxy radical, an alkylamino radical, an arylamino radical or an aralkylamino radical.

2. Method according to claim 1, wherein said colourless coupler compound is a non-diifusible colour coupler present in a silver halide emulsion layer or in another colloid layer which is in water-permeable relationship with said silver halide emulsion layer of said photographic material.

3. A photographic emulsion for preparing a photographic element for forming coloured images comprising a water-permeable colloid as carrier for light-sensitive silver halide and a colourless 2-pyrazolin-5-one colour coupler corresponding to the general formula:

wherein:

Ar represents an aryl group, and R represents an alkyl radical, an aryl radical, an aralkyl radical, an alkoxy radical, an aryloxy radical, an aralkyloxy radical, an alkylamino radical, an arylamino radical or an aralkylamino radical, at least one of Ar and R comprising an aliphatic radical having from 5 to 20 carbon atoms in straight line. 5. A photographic element according to claim 4, wherein said colour coupler is present in said emulsion layer.

References Cited UNITED STATES PATENTS 9/1940 Kendall et al. 96-565 5/1969 Menzel et a1 96-100 J. TRAVIS BROWN, Primary Examiner US. Cl. X.R. 

